title: Protonation of epigallocatechin-3-gallate (EGCG) results in massive aggregation and reduced oral bioavailability of EGCG-dispersed selenium nanoparticles.
abstract: The current results show that epigallocatechin-3-gallate (EGCG), in the form of phenolic anions at pH 8.0, can effectively disperse selenium nanoparticles. However, at gastric juice pH (1.0), the EGCG-dispersed selenium nanoparticles (referred to as E-Se) extensively aggregated, so that nano features largely disappeared. This demonstrates that deprotonated phenolic anions of EGCG play an important role in maintaining E-Se stability and suggests that E-Se would suffer from reduced oral bioavailability. To validate this conjecture, size-equivalent E-Se and bovine serum albumin (BSA)-dispersed selenium nanoparticles (B-Se), whose physicochemical properties were not altered at pH 1.0, were orally administered to selenium-deficient mice. In comparison to B-Se, the bioavailabilities of E-Se as indicated with hepatic and renal glutathione peroxidase activity and hepatic selenium levels were significantly (p < 0.01) reduced by 39, 32, and 31%, respectively. Therefore, the present study reveals that size-equivalent selenium nanoparticles prepared by different dispersers do not necessarily guarantee equivalent oral bioavailability.
authors.affiliation: Key Laboratory of Tea Biochemistry and Biotechnology, School of Tea and Food Science, Anhui Agricultural University, Hefei 230036, Anhui, People's Republic of China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wu
authors.forename: Kang
authors.initials: K
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Dongxu
authors.initials: D
authors.lastname: Wang
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wan
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001682:Biological Availability; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D002626:Chemistry, Pharmaceutical; D019587:Dietary Supplements / Q000032:analysis; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D010316:Particle Size; D012643:Selenium / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D012710:Serum Albumin, Bovine; D002392:Catechin; C045651:epigallocatechin gallate; D012643:Selenium